Your husband has a number of risk factors for coronary artery disease (blocked blood supply to the heart muscle) which I believe will be being controlled by his cardiologist. If he continues to have chest pain despite the stent implantation, it is important to make his cardiologist aware of this. His cardiologist may wish to consider a stress to evaluate for any remaining significant blocks.
Adding a bit to Ed34's explanation, my reports generally have used the term 'stunned' cells in referenced to the damaged cells that surround the dead heart tissue areas, and exercise and drugs can sometimes revitalize them. Hopefully your husband has nitro tablets or spray that he can take to relax his heart arteries during angina hits.
That said, it is possible that the stents can plug soon after inplantation, or sometimes when stents are inserted, it can cause the heart artery to spasm. He should contact his doctor about the reoccuring heart pressure/pain.
It all depends on the timing of the revascularisation. When having a heart attack, the blood supply is cut off from a section of heart muscle. This muscle starts to die in a matter of minutes. Depending how soon treatment is received, determines how much muscle dies. Once it dies, the muscle never regenerates or recovers. Some of the heart muscle could have been in a state of damage, before death, and this usually recovers over a couple of months. I think your Husband needs either an echo, or a nuclear scan to establish if any necrosis did occur, and how much.